QUOTE: "Should the United States instead choose to withdraw from Iraq before adequate security is established, we will exchange for this victory a defeat that is terrible and long-lasting."

KEY QUESTION: "What's the lesson that we're to draw from that (the troubled recent Iraqi offensive in Basra), that a thousand Iraqi army and police deserted or underperformed?"

PETRAEUS: "Well, one lesson, senator, is that relatively new forces — what happened was in one case a brigade that literally had just come out of (retraining) was pressed into operation. The other lesson is a recurring one, and that is the difficulty of local police operating in areas where there is serious intimidation of themselves and of their families."

DEMOCRAT HILLARY CLINTON

STANCE: Withdraw one to two brigades per month; require President Bush to seek congressional approval to any plan with Iraqis to continue operations beyond July.

OPENING: "I just want to respond to some of the statements and suggestions that have been made leading up to this hearing, and even during it, that it is irresponsible or demonstrates a lack of leadership to advocate withdrawing troops from Iraq in a responsible and carefully planned withdrawal. I fundamentally disagree."

KEY QUESTION: "There clearly are limits to the blood and treasure we can expend in an effort. What conditions would have to exist for you to recommend to the president that the current strategy is not working?"

PETRAEUS: "There is not an equation in which you have coefficients in front of each of these factors. It's not as mechanical as that ... it really involves commanders sitting down, also with their Iraqi counterparts and leaders in a particular area, and assessing where it is that you can reduce your forces."

DEMOCRAT BARACK OBAMA

STANCE: Withdraw one to two brigades per month; the surge has temporarily reduced violence but not yielded enough self-governance.

STYLE: Professorial, consensus-seeking; said Petraeus, Crocker are just "cleaning up the mess."

QUOTE: "There's a bipartisan consensus that we have finite resources. Our military is overstretched and the Pentagon has acknowledged it. The amount of money we're spending is hemorrhaging our budget. And al Qaida in Afghanistan, I think, is feeling a lot more secure as long as we're focused on Iraq. When you have finite resources you've got to define your goals tightly and modestly."

KEY QUESTION: "If we were able to have the status quo in Iraq right now without U.S. troops, would that be a sufficient definition of success? Or would that not be good enough and we'd have to devote even more resources to it?"

CROCKER: "When Iraq gets to the point that it can carry forward its further development without a major commitment of U.S. forces ...without significant danger of having the whole thing slip away from them again, then clearly our profile, our presence, diminishes markedly. But that's not where we are now."